|  | 5.3 | IP Routing Protocols
| 5.3.6 | IP routing configuration: Choosing a routing protocol
Each routing protocol must be configured separately. With any routing protocol, you must follow two basic steps: Create the routing process with one of the router commands. Configure the protocol specifics. As you learned earlier, the interior protocols such as IGRP and RIP must have a list of networks specified before routing activities can begin. In addition, you learned that the routing process listens to updates from other routers on these networks and broadcasts its own routing information on those same networks. IGRP has the additional requirement of an autonomous system (AS) number. With any of the IP routing protocols, you need to create the routing process, associate networks with the routing process, and customize the routing protocol for your particular network. Choosing a routing protocol is a complex task. When choosing a routing protocol, you should consider the following: Network size and complexity Network traffic levels Security needs Reliability needs Network delay characteristics Organizational policies Organizational acceptance of change
| Threaded Case Study
| Washington Project: AS Numbers AS number consistency is a design issue. You need to have the same number throughout the Washington School District network. The AS is assigned a 16-bit number by the Internet Assigned Numbers Authority.